Abstract

Mig1 is a zinc finger protein that mediates glucose repression in the yeast Saccharomyces cerevisiae. It is related to the mammalian Krox/Egr, Wilms' tumor, and Sp1 proteins and binds to a GC-rich motif that resembles the GC boxes recognized by these proteins. We have performed deletion mapping in order to identify functional domains in Mig1. We found that a small C-terminal domain comprising the last 24 amino acids mediates Mig1-dependent repression of a reporter gene. This effector domain contains several leucine-proline dipeptide repeats. We further found that inhibition of Mig1 activity in the absence of glucose is mediated by two internal elements in the Mig1 protein. A Mig1-VP16 hybrid activator was used to further investigate how Mig1 is regulated. Mig1-VP16 can activate transcription from promoters containing Mig1-binding sites and suppresses the inability of Snf1-deficient cells to grow on certain carbon sources. We found that a deletion of the SNF1 gene increases the activity of Mig1-VP16 fivefold under derepressing conditions but not in the presence of glucose. This shows that the hybrid activator is under negative control by the Snf1 protein kinase. Deletion mapping within Mig1-VP16 revealed that regulation of its activity by Snf1 is conferred by the same internal elements in the Mig1 sequence that mediate inhibition of Mig1 activity in the absence of glucose.

Interaction Annotations

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the
page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column
header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small
"i" buttons located within a cell for an annotation to view further details about experiment type and any other
genes involved in the interaction.

Gene Ontology Annotations

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page
scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header
to sort by that column; filter the table using the "Filter" box at the top of the table.

Phenotype Annotations

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page
scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header
to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i"
buttons located within a cell for an annotation to view further details.

Regulation Annotations

Increase the total number of rows displayed on this page using the pull-down located below the table, or use the
page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column
header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box
(for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to
further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Expression Datasets

Increase the total number of rows displayed on this page using the pull-down located below the table, or use the
page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column
header to sort by that column; filter the table using the "Filter" box at the top of the table; download this table
as a .txt file using the Download button;